Wallboard and joint made therewith



Oct. 4,1932. -T. B. MUNROE' 4 1,881,420

WALLB OARD AND JOINT MADE THEREWITH I I I Fi'ledMarch 10, 1930 2Sheets-Sheet 1 I u meg Oct. 4, 1932. T. B. MUNROE WALLBOARD AND JQEINTMADE THEREWITI-l Filed March 10. 19:50

, 2 Sheets-Sheet 2 Gnnentor Gttorneg laid in accordance with thisinvention; Figs. 2 and 3 illustrate 1n transverse secthe room side;

Patented Oct. 4 1932 I UNITED STATES PATENT oFFicE TREADWAY B. MUNROE,OF CHICAGO, ILLINOIS, ASSIGNOB TO THE .CEIDTEX COMPANY, I 01CHICAGOfILLINOIS, A. CORPORATION OF DELAWARE WALLBOAB AND .rontngmnn'rn'nanwrrn Application and March 1t), 1930; Serial No. 434.725.

This invention relates to wallboard units and joints made therewithhaving for its object to provide a construction which is simple in partsand more eflicient in use than those heretofore proposed.

With these and other objects in view the invention resides in the noveldetails of construction and combinations of parts as will be disclosedmore fully hereinafter and particularly pointed out in the claims.

Referring to the accompanying drawings forming a part'of thisspecification in which like numerals designate likeparts in all theviews,

Fig. 1 is a perspective view of a corner of aroom the vertical walls ofwhich have beenprovided with wallboard units made and tional detailmodifications of the preferred joint illustrated in Fig. 6; I

- Fig. l'is a sectional view taken longitudinally of a board made inaccordance with this invention;

Fig. 5 is a perspective detail view of a section ot a completed wall,clearly showing the manner of laying the wallboard units on studding andthe application of plaster to Fig. 6 is a much enlarged sectional viewof the preferred form of joint construction between studs I Fig. 7 isanother modification of the joint contemplated by this invention; and

Fig. 8 is a sectional view taken transverse- 1y of a wallboard unit,this figure and Figure 4 being respectively vertlcal and hori-,.

zontal sections of a unit in position for attaching to studding.

It is well known that walls have heretofore been made .from a pluralityof units known as wallboards, plaster boards, etc., but one of theprincipal objections to said previously known types is thatwhen thefinishing coat of plaster or other material is'spread over the surfacesof the .units and allowed to dry,

there occurs a crack in said finish. Thetime at which said finish cracksis not always the same, due to varying conditions such as thickness ofthe finishing coat, temperature exopening into which the plaster -willflow to tremes, humidity, etc. A curious fact is that i these cracks, insubstantially all cases, occur. at 'a joint between two adjacentunderlying wallboard units. W U

The reason for this is that each wallboard unit as a whole is incapableof absorbing the maximum of expansion and contraction in. the wall andwhich therefore localizes at the joints. In other words, the prior knownwallboards have been formed as a rather compacted mass so that thereis-little or no give in the finished unit, resulting in the unit as awhole stretching and shrinking under the expansion and contractionencountered through changes of temperature, humidity, etc. 1

Heretofore walls have been constructed in sections with joints betweenthe sections formed by a "tongue fitting a complementary recess in theadjacent board to provide a lapping efi'ect. Also joints havebeenconstructed heretofore wherein one section has an edge which abutsthe edge oi: the next adjacent section. Still further, fiber boards havebeen proposed 7 having lap joints wherein the tongues are dimensionedand shaped so as to form a recess on one face of the board which, withthe similar and complementaryrecess of the adjacent board, provides agroove or increase its thickness at e joint. The pla'ster is thusreinforced'or-proyided with a rib by such construction, the purposebeing. to compensate for the buckling of the wallboard without crackingthe heavy plaster sheet. This invention extends beyond such heretoforeknown constructions as will presentlybe made clear. v

The purpose of this invention is to provide a wallboardwhich, while moreor less rigid,

,is so constructed that it will yield materiall I Therefore, wallboardsformed by felting.

brous stock are particularly brought within the scope of this invention,but other boards such'as plaster'boards and similar substantially rigidconstructions may also have them edges formed as hereinafter specifiedin order to prevent the applied sheets from .bemg. forced apart at theiradjacent edges wjthae sultant cracking of the finishing decoration Iapplied to the room surface of the wall,

which often occurs due to shrinkage-and vibration or settling of thebuilding. In the case of fibrous boards the fibers are first subj ectedto preliminary treatment which is sufficicnt to loosen the outerencrusting layers and cementitious material but insufficient to destroythe material characteristics of the fibers such as strength,flexibility, etc. These treated fibers are then formed into a sheet ofabout one-half inchthickness which is subsequently dried and cut intounits of suitable lengths and widths for convenient handling intransportation and commercial use. The dimensions of said units arepreferably made as multiples of the standard spacing of framing membersin building construction a popular size being sixteen inches by twelvefeet.

The edges of each unit are then acted upon by suitable cutters to formthe edges such as shown in Figures 4 and 8 although other outters can besubstituted whereby the edge formations shown in Figures 2, 8, and 7 maybe provided. Such a board is yieldable, porous, moisture absorbing andfree to give under expansion and contraction.

Such a. fibrous board, however, has presented a real building problem ofcompensating for the expansion and contraction, anti buckling or wavingaction of the boar without crtcking the plaster secured on the boards atthe joints thereof. Particularly'is this so because this type of boardreadily absorbs moisture and is provided on its faces with amultiplicity of extending fibers constituting a plaster receiving andsecuring face, which extending fibers serve to securely bond the plasterapplied thereto. This fiber board when laid therefore has a differentialof shrinkage or expansion of the board at the upper and lower portionsthereof as a result of which there is a tendency for the horizontalunsupported edges to move angularly, and this invention is particularlydirooted to the reduction if not total elimination of this positivemovement in the edge portions of the boards.

As will be more particularly pointed out later the multiplicity ofextending fibers on the plaster receiving face of'these boards securelylock the heavy plaster coating applied thereto. Further the edges ofthese boards are provided with bevel portions which, when the boards areassembled in the wall construction, constitute V-shaped grooves whichform a V shaped plaster rib having an extremely long line of diagonalreinforcement through the plaster at the joints. Since the boards arelaid with their long dimension crossing the studding there will be along line of V-shaped plaster rib extcnding'between and across thestuds;

Moisture will ordinarily cause; an outward bulging of the boards when inplace, resulting in cracks in the plaster. To overcome bond on the bevelportions of the boards,

causes such bevel to a certain extent to leave the plaster at theV-shaped groove whereby an angular movement of the tongue and recessconstituting the joint is permitted without placing any great strain onthe plaster. An additional and very important feature of this inventionlies in the provision of means to keep the adjoining horizontal edges incontact during such buckling or weaving thereby providing a positivelyclosed horizontal joint between the boards.

In the preferred form of construction the rectangular board 1 has itsparallel shorter edges trimmed by cutters as shown in Figure 4,providing an abutting edge surface 2 at each end which is perpendicularto the back face 3 of the board, and oblique surfaces 4 constitutingbevels disposed between the surfaces 2 and the front face 5 of theboard, said front face being parallel to the back face. In forming thewall of a room the boards are laid lengthwise across the studs 6, whichare placed in standard building construction on sixteen inch centers,with the vertical joint between two contiguous boards centered on a studas clearly indicated in Figures 1 and 5, nails being driven through theedge sections, of each board adjacent the bevels 4 into'the supportingstud, the board being secured to the intermediate studs as indicated at7.

The boards are laid in horizontal courses starting at the floor, thewall being built up tier by tier toward the ceiling with the verticaljoints staggered, as indicated at 8 in Figure 1, thus adding strength tothe finished wall, and creating a continuous horizontal oint 9,

The other, or longitudinal, edges of each --board are peculiarly formedso that one edge is trimmed to provide a shouldered recess or rabbet 10while on the other edge is formed a flange 11. In other words each boardhas one longitudinal edge formed with a rabbet and the'opposite parallellongitudinal edge formed with a flange, so that, when the units Figure5. In forming the or flange 12, and

left an extending portion the front face 5 is provided with edge bevels13 and 14, the former bevel formed on the flange 12 and the latter bevelmeeting the inner extremity of the flange 11.

all four edges;

-' However, each rabbet andthe flange com} face 15 of the rabbet is notformed perpendi'e Thus the. room side of the board has similar bevels oni i is (Eli

u arly to the rear face 3 of the board but is cut obliquely thereto toform an edge portion 16 of acute cross-section extending over a portionof the rabbet; Likewise the ex- 5 treme end of the flange 11 is notformed perpendicularly to the plane of the board but is provided with asurface 17 parallel to the surface 15, and since all boards aresimilarly formed, it will readily be seen that, when the boards arenailed to the studs in a'common plane, the surface 15 ofone board willcontactingly coincide with the surface 17 of the .adjacentboard.Further, the inclination of these surfaces will cause a tighterengageward pressure is applied in securing a board of an upper course,the edge 18 of the flange of the upper board being locked in the rabbetof the board therebelow, and the bevels 13 and it forming a V-shapedgroove into which the plaster or other decorative finishing coat '25 mayextend for reinforcement. The bevels 4: along the shorter sides of theboards provide a similar V-shaped groove forming the reinforcing rib 26in the plastic wall finish which lies in registry with a stud 6.Therefore it will be seen that this provides a reinforcing rib in thewall finish at the joints between the hoards which overcomes thecracking of said finish at these points. lln this connectionit should bestated that the cutters in forming the bevels i, 13 land M leave thesesurfaces relatively smooth as compared to the rough faces 3 and 5 withtheir extending fiber ends. Therefore, the plastic coating will bestrongly bonded to the rough face 5 butwill be less strongly bonded onthe aforesaid bevels so that, during the expansion and contraction ofthe boards inthe wall, the beveled surfaces may leavethe reinforcingplastic ribs and thus prevent the transfer of the cracking strains tothe plaster.

ln Figure 2 the construction is as hereto fore described withtheexception that the combined thickness of the flanges ll and '12 isless than the thickness of the board with the result that two adjacenthoards will have formed at their joint and between said flanges a space30 into which the plaster or finishing coat 25 may keyingly enter asindicatedlat 31 to additionally hold the plaster coat to the Figure 3illustrates a joint exactly like that shown in Figure 6 except thatinstead of a V-shaped plaster receiving groove there is provided arectangular groove formed by the surfaces 32 and 33 each perpendicularto the face 5 of the board. Also the heretofore dement of the adjoiningboards when 'down- 1 that the recess 10 is thus provided with scribedflange 12 has been shortened in length in this modification;

In the form of jointshown in Figure 7 the bevels 13 and 14 are replacedby curved surfaces 34 and 35 respectively whereby the plasterreinforcing rib 36 is strengthened by the elimination of angles betweensaid rib and the main plaster sheet. Also,vin this modification, theplane surfaces 15 and 17 heretofore described are replaced by the curvedsurfaces 37 and 38 respectively, the chordal plane of each curvedsurface having substantially the same degree ofinclinationto the planeof the rear face 3 of-the board as the plane of the surface 15 in theform construction shown in Figure 8, whereby a locked joint is assured.

Thus it will be seen that by this invention there is provided a jointbetween two contiguous wallboards placed in edge to edge relation, whichis formed by two flanges, one flange complementally fitting an undercutrabbet formed adjacent the other flange whereby the joint is retainedclosed under pressures applied transversely to the joint. Thisparticular joint is a lap joint or one wherein the two flanges areformed at the corners of each board as contradistinguished from the wellknown tongue and groove joint, each flange being formed by a recess cutin the other corner ofthe same edge of the board. Further it is to beparticularly noted that the pocket 19 is formed by the sur-. face 15which extends beyond the limit of said pocket whereby the corner 16truly projects or overhangs said pocket, all to the end an undercutend.'

lit is obvious that those skilled in the art I may vary the details ofconstruction and arthis application isan improvement-thereof.

What is claimed is 2-- 1., A heat insulating wallboard plaster base ofyielding fibrous and moisture absorbable character comprising aplurality of boards set edge to edge, the adjacent edges of the boardsbeing bevelled to form a substantially V-shaped groove adapted to'receive plaster, the edge of one board being provided with a recess andthe edge of the other board being provided with a tongue fitting withinthe recess the outer end of the tongue and base of the recesscomplementally relieved to interlock and form a self-sealed heatinsulating jointi 2. A heat insulating wallboard plaster base ofyielding fibrous and moistureabsorb-- able character comprising aplurality of boards set edge to edge, the adjacent edges of the boardsbeing bevelled to form a substantially V-shaped groove adapted toreceive plaster, the edge of one board being provided with a recess andthe edge of the other board being provided with a tongue fitting withinthe recess the outer end of the tongue and base of the recesscomplementally relieved to interlock and form a self-sealed heatinsulating joint, said V-shaped groove being slightly offset relative tosaid joint.

3. A heat insulating wallboard fibrous base of yielding fibrous andmoisture absorbbase of yielding fibrous and moisture absorbablecharacter comprising a plurality of boards set edge to edge, thelongitudinally disposed edges of the boards being bevelled to form asubstantially V-shaped longitudinally disposed groove, the edge of oneboard being provided with a recess and the edge of the other board beingprovided with a tongue fitting within the recess the outer end of thetongue and base of the recess complementally relieved to interlock andform a self-sealed insulating joint, the abutting vertical edges of saidboards being also bevelled to provide a vertically disposed groove.

5. A wallboard of yielding fibrous nature having an edge formed with aprotruding flange at the bottom thereof and with a bevel extending fromthe inner end of .the flange rearwardly to the top of the board, and theopposite edge of the board provided with a rabbeted portion forming arecess on the under side thereof and having formed on its upper side abevelled portion extending from the top of the board rearwardly to theend.

of said rabbeted portion, the base face of said rabbeted recess and theend face of said flange being complementally relieved for interlockingengagement respectively with complementing flanges and rabbeted recessesof adjacent boards.

6. As a new article of manufacture a board having at its opposite edgesrecesses respectively facing in opposite directions at opposite sides ofthe board thereby forming on each edge an extending flange, the innerend of one of said recesses being undercut to form a pocket, and the endof the flange on the opposite edge of the board complementally formedwith respect to said pocket.

7. As an article of manufacture a-plaster base composition fiber boardun1t having opposite edges provided with reinforcedfianges respectivelyfacing in opposite directions at opposite face sides of the boards, saidedges being provided with bevelled portions on the outer face of theboard, one bevelled portion extending from the end of one flange, theother extending from the base of the other flange, said flanges beingadapted to complement similar flanges of other boards when set edgeto-edge to form a heat insulating joint, one of said flanges relievedfrom its end toward the. adjacent board face, the other flange havingformed at its base a complementing recess,

8. A plaster basewall board unit having oppositely bevelled eiid edgesand oppositely bevelled side edges, one of the side edgeshaving a rabbettherein and the otherside edge having a flange thereon, the rabbet atits base and said flange at its en'dcomplementally relieved to provide alocked joint with a similarly formed board when said boards are set edgeto edge.

9. A plaster base wall board unit provided around all the edges thereofwith a bevel on the front side of the board,'whereby when the boards areapplied with the edges in consaid board having one a rabbet and theother a flange on the rear side of the board, said rabbet at its baserelieved inwardly from the adjacent board face and said flange at itsend complementally relieved and engageable with similar portions of anadjacent board to form a closed joint unyielding when plaster is appliedthereover.

10. A plaster base wall board unit having oppositely bevelled sideedges, the side edges having a rabbet in one edge and a flange on,

the other, said rabbet at its'base relieved inwardly from the adjacentboard face, and the flange at its end complementally relieved andfashioned for interlocking engagement with a flange and a rabbet of asimilarly formed board when set in edge to edge rela tion.

11. A wall comprising a pluralityof adjoining plaster receiving boardunits having lapped joints comprising overlapping portions of reducedthickness along the opposite edges of the units, recesses on the outerside along said joints and plaster applied to the outer sides of theunits and filling said re cesses to form added thickness of plaster atsaid joints, the underlying lap edges of said units relieved from theirends toward the adjacent unit face to enter complementally relievedportions of adjacent units and be wedgingly engaged, whereby the jointsremain closed during the application 'of the plaster as well as underboa-rd yielding ini 12. An insulated wall comprising spaced studdingmembers, plaster receiving fiber board units adapted to prevent thepassage of heat applied and securedv edge to edge thereto, each boardadapted to form with the adjacent boards lap joints extending across andbetween saidstudding, said lap joints I comprising complementing flangeand rabbet portions on-the edges of adjacent boards, the edge of anunderlying flange relieved at its end inwardly to the adjacent boardface, the

' rabbet at its base complementally relieved to provide coactingvWedging portions whereby the passage of heat is further prevented at allsaid joints, recesses on the outer side of said boards along said jointsand a plaster sheet applied to the outer sides of the boards and fillingsaid recesses, to form added thickness of plaster at said joints,whereby there is produced a plasterreinforced structure.

13. A plaster base comprising a series of plaster receiving board unitsadapted to be arranged adjacent to each other in the same plane, andhaving roughened outer surfaces for holding a sheet of-plaster appliedto the base, each of said boards being provided at opposite edges withreverse flanges adapted to overlap and complement similar flanges ofadjoining boards, the under flange of each board unit having a reducedend portion interlocking with a complementing recess formed at the edgeof the adjoining board.

In testimony whereof I aflix m signature,

TREADWAY; ROE.

